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Lezza AMS, Fallacara FP, Pesce V, Leeuwenburgh C, Cantatore P, Gadaleta MN. Localization of abasic sites and single-strand breaks in mitochondrial DNA from brain of aged rat, treated or not with caloric restriction diet. Neurochem Res 2008; 33:2609-14. [PMID: 18946734 DOI: 10.1007/s11064-008-9866-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 10/03/2008] [Indexed: 11/24/2022]
Abstract
According to the "mitochondrial theory of aging" the lifelong accumulation of various kinds of damage to mitochondrial DNA (mtDNA) has been related to the age-dependent mitochondrial bioenergetic dysfunction. Caloric restriction (CR) diet is able to prevent or delay the onset of several age-related damages to mtDNA. The effects of aging and CR on the presence of abasic sites and single-strand breaks of the sugar-phosphate backbone in mtDNA have been analyzed by applying Ligation Mediated-PCR to a H strand region of brain mtDNA from young and old ad libitum-fed and old CR-treated rats. The region, encompassing the Direct Repeat 1 of the 4,834 bp-long deletion, is highly damaged in the old ad libitum-fed animals with respect to the young ones, whereas in the CR rats it shows a much lower extent of damage. The data confirm, at single nucleotide resolution, the protective effect of CR on the age-related mtDNA damage.
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Affiliation(s)
- A M S Lezza
- Department of Biochemistry and Molecular Biology Ernesto Quagliariello, University of Bari, Via Orabona, 4, 70125, Bari, Italy
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Cassano P, Sciancalepore AG, Pesce V, Flück M, Hoppeler H, Calvani M, Mosconi L, Cantatore P, Gadaleta MN. Acetyl-l-carnitine feeding to unloaded rats triggers in soleus muscle the coordinated expression of genes involved in mitochondrial biogenesis. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2006; 1757:1421-8. [PMID: 16814248 DOI: 10.1016/j.bbabio.2006.05.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/09/2006] [Accepted: 05/12/2006] [Indexed: 12/30/2022]
Abstract
The expressional profile of mitochondrial transcripts and of genes involved in the mitochondrial biogenesis pathway induced by ALCAR daily supplementation in soleus muscle of control and unloaded 3-month-old rats has been analyzed. It has been found that ALCAR treatment is able to upregulate the expression level of mitochondrial transcripts (COX I, ATP6, ND6, 16 S rRNA) in both control and unloaded animals. Interestingly, ALCAR feeding to unloaded rats resulted in the increase of transcript level for master factors involved in mitochondrial biogenesis (PGC-1alpha, NRF-1, TFAM). It also prevented the unloading-induced downregulation of mRNA levels for kinases able to transduce metabolic (AMPK) and neuronal stimuli (CaMKIIbeta) into mitochondrial biogenesis. No significant effect on the expressional level of such genes was found in control ALCAR-treated rats. In addition, ALCAR feeding was able to prevent the loss of mitochondrial protein content due to unloading condition. Correlation analysis revealed a strong coordination in the expression of genes involved in mitochondrial biogenesis only in ALCAR-treated suspended animals, supporting a differentiated effect of ALCAR treatment in relation to the loading state of the soleus muscle. In conclusions, we demonstrated the ability of ALCAR supplementation to promote only in soleus muscle of hindlimb suspended rats an orchestrated expression of genes involved in mitochondrial biogenesis, which might counteract the unloading-induced metabolic changes, preventing the loss of mitochondrial proteins.
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Affiliation(s)
- P Cassano
- Department of Biochemistry and Molecular Biology Ernesto Quagliariello, University of Bari- Via Orabona 4- 70125, Bari, Italy
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Cassano P, Sciancalepore AG, Lezza AMS, Leeuwenburgh C, Cantatore P, Gadaleta MN. Tissue-Specific Effect of Age and Caloric Restriction Diet on Mitochondrial DNA Content. Rejuvenation Res 2006; 9:211-4. [PMID: 16706645 DOI: 10.1089/rej.2006.9.211] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effect of age and caloric-restriction (CR) diet on mitochondrial DNA (mtDNA) content in different rat tissues was investigated. A decrease of the mtDNA content occurs with aging in liver and soleus muscle, whereas there is no age-related significant change of mtDNA content in brain. CR fully reverses the age-dependent loss of mtDNA in liver and soleus, whereas it results in a significant increase of mtDNA amount above the value of aged ad libitum fed rats in brain. These results further support the tissue-specific effect of CR, likely because of the different dependence of tissues on external nutrient uptake.
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Affiliation(s)
- P Cassano
- Department of Biochemistry and Molecular Biology, University of Bari, Bari, Italy.
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Petruzzella V, Baggetto LG, Penin F, Cafagna F, Ruggiero FM, Cantatore P, Gadaleta MN. In vivo effect of acetyl-L-carnitine on succinate oxidation, adenine nucleotide pool and lipid composition of synaptic and non-synaptic mitochondria from cerebral hemispheres of senescent rats. Arch Gerontol Geriatr 2005; 14:131-44. [PMID: 15374398 DOI: 10.1016/0167-4943(92)90048-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/1991] [Revised: 10/30/1991] [Accepted: 11/07/1991] [Indexed: 11/22/2022]
Abstract
The effect of acetyl-L-carnitine on succinate oxidation, adenine nucleotide pool and lipid composition of synaptic and 'free', non-synaptic, mitochondria in cerebral hemispheres of senescent rats has been studied. Fisher rats (24- or 28-month-old) were treated with acetyl-L-carnitine (300 mg/kg body wt., intraperitoneally (i.p.)) 3 h before being killed. Oxygen consumption was measured using succinate as a substrate; adenine nucleotides and lipids were analyzed by high performance liquid chromatography (HPLC). Acetyl-L-carnitine reverses, in synaptic mitochondria, the age-related decrease in the respiratory control ratio due to a higher state 4 respiration rate. Administration of acetyl-L-carnitine to senescent rats does not affect the total adenine nucleotide pool of synaptic and non-synaptic mitochondria which was unchanged with age. Finally, pretreatment of senescent rats with acetyl-L-carnitine brings the cholesterol and phospholipid contents of synaptic mitochondria, reduced in senescent rats, to the adult level; pretreatment of adult rats has no such effect. Altogether these results suggest that acetyl-L-carnitine is able to reverse age-related deficits of brain mitochondria.
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Affiliation(s)
- V Petruzzella
- Dipartimento di Biochimica e Biologia Molecolare e Centro Studi su Mitocondri e Metabolismo Energetico, Università di Bari, Bari, Italia
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Cassano P, Lezza AMS, Leeuwenburgh C, Cantatore P, Gadaleta MN. Measurement of the 4,834-bp mitochondrial DNA deletion level in aging rat liver and brain subjected or not to caloric restriction diet. Ann N Y Acad Sci 2004; 1019:269-73. [PMID: 15247027 DOI: 10.1196/annals.1297.045] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Several studies have demonstrated an age-related accumulation of the amount of a specific 4834-bp mitochondrial DNA (mtDNA) deletion in different tissues of rat (liver, brain, and skeletal muscle). We investigated the influence of a caloric restriction diet (CR) on a selected age-associated marker of mtDNA damage, as the 4834-bp deletion, using quantitative real-time PCR. The mtDNA deleted level has been determined with respect to the mitochondrial D-loop level, using specific primers and TaqMan probes for each target. In liver we found an age-related increase of the deletion level (twofold) that was reversed and brought back to the adult level by a CR diet. On the contrary, in the brain the age-related increase of the deletion level (eightfold) was not affected by CR at all. The different effect of the CR on the deletion level in liver and brain might be a further element supporting the tissue-specificity of the aging process.
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Affiliation(s)
- P Cassano
- Department of Biochemistry and Molecular Biology, University of Bari, Bari, Italy.
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Pesce V, Fracasso F, Musicco C, Lezza AMS, Cantatore P, Gadaleta MN. Acetyl-l-Carnitine Dietary Supplementation to Old Rats Increases Mitochondrial Transcription Factor A Content in Rat Hindlimb Skeletal Muscles. Ann N Y Acad Sci 2004; 1019:430-3. [PMID: 15247059 DOI: 10.1196/annals.1297.077] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Acetyl-L-carnitine (ALCAR) fed to old rats has been reported to partially restore mitochondrial function and ambulatory activity. The results of the effect of ALCAR dietary supplementation to 28-month-old rats on mitochondrial transcription factor A (TFAM) content of rat hindlimb skeletal muscles are reported.
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Affiliation(s)
- V Pesce
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Pesce V, Cormio A, Fracasso F, Lezza AMS, Cantatore P, Gadaleta MN. Rat hindlimb unloading: Soleus and Extensor Digitorum Longus histochemistry, mitochondrial DNA content and mitochondrial DNA deletions. Biosci Rep 2002; 22:115-25. [PMID: 12418554 DOI: 10.1023/a:1016069208073] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mitochondrial phenotypic alterations, mitochondrial DNA content and mitochondrial DNA deletions in a slow, Soleus, and a fast, Extensor Digitorum Longus, skeletal muscle of 3- and 15-month-old hindlimb suspended rats have been studied. Cytochrome c oxidase-negative fibers appeared after unloading in all examined animals and their percentage increased with increasing unloading time. After 14 days of suspension the mitochondrial DNA content did not change in 3-month-old but decreased significantly in 15-month-old rats. Soleus was much more affected by unloading than Extensor Digitorum Longus. The mitochondrial DNA deletion of 4834 bp as well as other mtDNA deletions, researched with Long Distance-PCR, were absent in both studied muscles before and after unloading.
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Affiliation(s)
- V Pesce
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Fernandez-Silva P, Polosa PL, Roberti M, Di Ponzio B, Gadaleta MN, Montoya J, Cantatore P. Sea urchin mtDBP is a two-faced transcription termination factor with a biased polarity depending on the RNA polymerase. Nucleic Acids Res 2001; 29:4736-43. [PMID: 11713324 PMCID: PMC92518 DOI: 10.1093/nar/29.22.4736] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The sea urchin mitochondrial displacement (D)-loop binding protein mtDBP has been previously identified and cloned. The polypeptide (348 amino acids) displays a significant homology with the human mitochondrial transcription termination factor mTERF. This similarity, and the observation that the 3' ends of mitochondrial RNAs coded by opposite strands mapped in correspondence of mtDBP-binding sites, suggested that mtDBP could function as transcription termination factor in sea urchin mitochondria. To investigate such a role we tested the capability of mtDBP bound to its target sequence in the main non-coding region to affect RNA elongation by mitochondrial and bacteriophage T3 and T7 RNA polymerases. We show that mtDBP was able to terminate transcription bidirectionally when initiated by human mitochondrial RNA polymerase but only unidirectionally when initiated by T3 or T7 RNA polymerases. Time-course experiments indicated that mtDBP promotes true transcription termination rather than transcription pausing. These results indicate that mtDBP is able to function as a bipolar transcription termination factor in sea urchin mitochondria. The functional significance of such an activity could be linked to the previously proposed dual role of the protein in modulating mitochondrial DNA transcription and replication.
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Affiliation(s)
- P Fernandez-Silva
- Departamento de Bioquimica y Biologia Molecular y Celular, Universidad de Zaragoza, Miguel Servet 177, E-50013 Zaragoza, Spain
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Lezza AM, Pesce V, Cormio A, Fracasso F, Vecchiet J, Felzani G, Cantatore P, Gadaleta MN. Increased expression of mitochondrial transcription factor A and nuclear respiratory factor-1 in skeletal muscle from aged human subjects. FEBS Lett 2001; 501:74-8. [PMID: 11457459 DOI: 10.1016/s0014-5793(01)02628-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The expression of two factors involved in the nuclear-mitochondrial crosstalk, namely the mitochondrial transcription factor A (TFAM) and the nuclear respiratory factor-1 (NRF-1), was studied in human skeletal muscle biopsies of young and aged subjects. Aged subjects presented a 2.6-fold and an 11-fold increase of the levels of TFAM protein and TFAM mRNA, respectively. The increased expression of TFAM was associated to the doubling of NRF-1 DNA-binding affinity and to a 6-fold increase of NRF-1 mRNA level. The upregulation of TFAM and NRF-1, in aged skeletal muscle, appears involved in the pathway leading to the age-related increase of mitochondrial DNA content.
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Affiliation(s)
- A M Lezza
- Department of Biochemistry and Molecular Biology, university of Bari, and Center of Study on Mitochondria and Energetic Mechanism, CNR, Italy
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Pesce V, Cormio A, Fracasso F, Vecchiet J, Felzani G, Lezza AM, Cantatore P, Gadaleta MN. Age-related mitochondrial genotypic and phenotypic alterations in human skeletal muscle. Free Radic Biol Med 2001; 30:1223-33. [PMID: 11368920 DOI: 10.1016/s0891-5849(01)00517-2] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To have a clearer picture of how mitochondrial damages are associated to aging, a comprehensive study of phenotypic and genotypic alterations was carried out, analyzing with histochemical and molecular biology techniques the same skeletal muscle specimens of a large number of healthy subjects from 13 to 92 years old. Histochemical data showed that ragged red fibers (RRF) appear at about 40 years of age and are mostly cytochrome c oxidase (COX)-positive, whereas they are almost all COX-negative thereafter. Molecular analyses showed that the 4977 bp deletion of mitochondrial DNA (mtDNA(4977)) and the 7436 bp deletion of mtDNA (mtDNA(7436)) are already present in individuals younger than 40 years of age, but their occurrence does not change with age. After 40 years of age the number of mtDNA deleted species, as revealed by Long Extension PCR (LX-PCR), increases, the 10422 bp deletion of mtDNA (mtDNA(10422)) appears, although with a very low frequency of occurrence, and mtDNA content is more than doubled. Furthermore, mtDNA(4977) level directly correlates with that of COX-negative fibers in the same analyzed subjects. These data clearly show that, after 40 years of age, the phenotypic and genotypic mitochondrial alterations here studied appear in human skeletal muscle and that they are closely related.
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Affiliation(s)
- V Pesce
- Department of Biochemistry and Molecular Biology, University of Bari and Center for the Study of Mitochondria and Energetic Metabolism, Bari, Italy
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Musicco C, Roberti M, Polosa PL, Milella F, Sagliano A, Gadaleta MN, Cantatore P. Regulation of the expression of the sea urchin mitochondrial D-loop binding protein during early development. Biochem Biophys Res Commun 2000; 277:299-304. [PMID: 11032721 DOI: 10.1006/bbrc.2000.3670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Paracentrotus lividus mitochondrial D-loop binding protein (mtDBP) is a DNA-binding protein which is involved in the regulation of sea urchin mtDNA transcription. Immunoblots of Heparin Sepharose-bound proteins at selected early developmental stages, as well as electrophoretic mobility shift assay, show that mtDBP is present in the egg at a concentration of about 1 x 10(6) molecules/egg. Its level increases after fertilization of about twofold, remaining substantially unchanged between 16-h blastula stage and early pluteus stage and declines thereafter. The content of mtDBP mRNA, determined by RNase protection experiments, increases about sevenfold at the 16-h blastula stage compared to the egg. A considerable decrease occurs at the 40-h pluteus stage, which precedes that of the protein. These results suggest that the expression of mtDBP is regulated at transcriptional level up to blastula stage, while other factors, in addition to the level of the RNA, may control the content of this protein in the following stages of embryogenesis.
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Affiliation(s)
- C Musicco
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, Via Orabona 4, Bari, 70126, Italy
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Cormio A, Lezza AM, Vecchiet J, Felzani G, Marangi L, Guglielmi FW, Francavilla A, Cantatore P, Gadaleta MN. MtDNA deletions in aging and in nonmitochondrial pathologies. Ann N Y Acad Sci 2000; 908:299-301. [PMID: 10911970 DOI: 10.1111/j.1749-6632.2000.tb06658.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A Cormio
- Department of Biochemistry and Molecular Biology, University of Bari, Italy.
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13
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Paradies G, Petrosillo G, Gadaleta MN, Ruggiero FM. The effect of aging and acetyl-L-carnitine on the pyruvate transport and oxidation in rat heart mitochondria. FEBS Lett 1999; 454:207-9. [PMID: 10431808 DOI: 10.1016/s0014-5793(99)00809-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The effect of aging and acute treatment with acetyl-L-carnitine on the pyruvate transport and oxidation in rat heart mitochondria was studied. The activity of the pyruvate carrier as well as the rates of pyruvate-supported respiration were both depressed (around 40%) in heart mitochondria from aged rats, the major decrease occurring during the second year of life. Administration of acetyl-L-carnitine to aged rats almost completely restored the rates of these metabolic functions to the level of young control rats. This effect of acetyl-L-carnitine was not due to changes in the content of pyruvate carrier molecules. The heart mitochondrial content of cardiolipin, a key phospholipid necessary for mitochondrial substrate transport, was markedly reduced (approximately 40%) in aged rats. Treatment of aged rats with acetyl-L-carnitine reversed the age-associated decline in cardiolipin content. As the changes in cardiolipin content were correlated with changes in rates of pyruvate transport and oxidation, it is suggested that acetyl-L-carnitine reverses the age-related decrement in the mitochondrial pyruvate metabolism by restoring the normal cardiolipin content.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy.
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14
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Lisowsky T, Polosa PL, Sagliano A, Roberti M, Gadaleta MN, Cantatore P. Identification of human GC-box-binding zinc finger protein, a new Krüppel-like zinc finger protein, by the yeast one-hybrid screening with a GC-rich target sequence. FEBS Lett 1999; 453:369-74. [PMID: 10405178 DOI: 10.1016/s0014-5793(99)00754-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new human zinc finger DNA-binding protein was identified by using a yeast one-hybrid selection system. Two versions of the cDNA, encoding the same protein, were detected that differ for a 584 bp extension at the 5' region. Sequence analysis showed that the longer clone is a full length version containing part of the 5' untranslated region. The smaller version was fused in frame with the yeast GAL4 activation domain whereas the 5' region of the longer clone displayed a stop codon interrupting the fusion with the GAL4 domain. Nevertheless, this clone activated the yeast HIS3 reporter gene with the same efficiency as the smaller version. Sequence comparison of the derived protein with the database showed that it belongs to a family of zinc finger DNA-binding proteins which regulate the expression of genes involved in cell proliferation. Expression of the protein in an in vitro system, DNA-binding studies and genetic experiments identify this factor as a new zinc finger DNA-binding protein which binds GC-rich sequences and contains a domain probably functioning as a transcriptional activator. The new human protein identified in this study was therefore named GC-box-binding zinc finger protein).
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Affiliation(s)
- T Lisowsky
- Botanisches Institut, Heinrich-Heine-Universität Düsseldorf, Germany
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Lezza AM, Mecocci P, Cormio A, Beal MF, Cherubini A, Cantatore P, Senin U, Gadaleta MN. Mitochondrial DNA 4977 bp deletion and OH8dG levels correlate in the brain of aged subjects but not Alzheimer's disease patients. FASEB J 1999; 13:1083-8. [PMID: 10336891 DOI: 10.1096/fasebj.13.9.1083] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The levels of mitochondrial DNA 4977 bp deletion (mtDNA4977) and mitochondrial DNA 8'-hydroxy-2'-deoxyguanosine (OH8dG) were determined in the same samples from two brain areas of healthy subjects and Alzheimer's disease (AD) patients. A positive correlation between the age-related increases of mtDNA4977 and of OH8dG levels was found in the brain of healthy individuals. On the contrary, in both brain areas of AD patients, mtDNA4977 levels were very low in the presence of high OH8dG amounts. These results might be explained assuming that the increase of OH8dG above a threshold level, as in AD patients, implies consequences for mtDNA replication and neuronal cell survival.
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Affiliation(s)
- A M Lezza
- Department of Biochemistry and Molecular Biology, University of Bari, 70125 Bari, Italy
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16
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Loguercio Polosa P, Roberti M, Musicco C, Gadaleta MN, Quagliariello E, Cantatore P. Cloning and characterisation of mtDBP, a DNA-binding protein which binds two distinct regions of sea urchin mitochondrial DNA. Nucleic Acids Res 1999; 27:1890-9. [PMID: 10101198 PMCID: PMC148398 DOI: 10.1093/nar/27.8.1890] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The cDNA for the sea urchin mitochondrial D-loop-binding protein (mtDBP), a 40 kDa protein which binds two homologous regions of mitochondrial DNA (the D-loop region and the boundary between the oppositely transcribed ND5 and ND6 genes), has been cloned. Four different 3'-untranslated regions have been detected that are related to each other in pairs and do not contain the canonical polyadenylation signal. The in vitro synthesised mature protein (348 amino acids), deprived of the putative signal sequence, binds specifically to its DNA target sequence and produces a DNase I footprint identical to that given by the natural protein. mtDBP contains two leucine zippers, one of which is bipartite, and two small N- and C-terminal basic domains. A deletion mutation analysis of the recombinant protein has shown that the N-terminal region and the two leucine zippers are necessary for the binding. Furthermore, evidence was provided that mtDBP binds DNA as a monomer. This rules out a dimerization role for the leucine zippers and rather suggests that intramolecular interactions between leucine zippers take place. A database search has revealed as the most significative homology a match with the human mitochondrial transcription termination factor (mTERF), a protein that also binds DNA as a monomer and contains three leucine zippers forming intramolecular interactions. These similarities, and the observation that mtDBP-binding sites contain the 3'-ends of mtRNAs coded by opposite strands and the 3'-end of the D-loop structure, point to a dual function of the protein in modulating sea urchin mitochondrial DNA transcription and replication.
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Affiliation(s)
- P Loguercio Polosa
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and the Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, Via Orabona 4, 70125 Bari, Italy
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Roberti M, Polosa PL, Musicco C, Milella F, Qureshi SA, Gadaleta MN, Jacobs HT, Cantatore P. In vivo mitochondrial DNA-protein interactions in sea urchin eggs and embryos. Curr Genet 1999; 34:449-58. [PMID: 9933356 DOI: 10.1007/s002940050419] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Footprinting studies with the purine-modifying agent dimethyl sulphate were performed in Paracentrotus lividus eggs and embryos to analyze in vivo the interactions between protein and mitochondrial DNA. Footprinting in the small non-coding region and at the boundary between the ND5 and ND6 genes revealed two strong contact sites corresponding with the in vitro binding sequences of mitochondrial D-loop-Binding Protein (mtDBP). The analysis of the pause region of mtDNA replication showed a strong footprint corresponding with the binding site of the mitochondrial Pause region-Binding Protein-2 (mtPBP-2), but only a very weak signal at the binding site of the mitochondrial Pause region-Binding Protein-1 (mtPBP-1), which in vitro binds DNA with high efficiency. In vitro and in vivo analysis of the 3' end-region of the two rRNA genes showed no significant protein-DNA interactions, suggesting that, in contrast to mammals, the 3' ends of sea urchin mitochondrial rRNAs are not generated by a protein-dependent transcription termination event. These and other data support a model in which expression of mitochondrial genes in sea urchins is regulated post-transcriptionally. Footprinting at the five AT-rich consensus regions allowed the detection of a binding site in the non-coding region for an as-yet unidentified protein, mtAT-1BP. The occupancy of this site appears to be developmentally regulated, being detectable in the pluteus larval stage, but not in unfertilized eggs.
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Affiliation(s)
- M Roberti
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy
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Abstract
Aging is a complex physiological phenomenon and several different theories have been elaborated about its origin. Among such theories, the 'mitochondrial theory of aging', which has gained a large support, indicates the accumulation of somatic mutations of mitochondrial DNA leading to the decline of mitochondrial functionality as one of the driving forces for the process itself. In this review data on rat and man from our laboratory and from recent literature have been thoroughly examined and compared in order to provide the 'state-of-the-art' on the role of mitochondria in aging. Alterations of structure and expression of mitochondrial genome with aging, to find out the eventual relevant changes of mitochondrial biogenesis, have been studied in rat whereas the relationship between cytochrome c oxidase activity and 'common deletion' has been studied in man. Results on the effect of acetyl-L-carnitine on the mitochondrial functionality are also reported.
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Affiliation(s)
- M N Gadaleta
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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19
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Cantatore P, Petruzzella V, Nicoletti C, Papadia F, Fracasso F, Rustin P, Gadaleta MN. Alteration of mitochondrial DNA and RNA level in human fibroblasts with impaired vitamin B12 coenzyme synthesis. FEBS Lett 1998; 432:173-8. [PMID: 9720919 DOI: 10.1016/s0014-5793(98)00857-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alterations of mitochondrial (mt) nucleic acid metabolism in methylmalonic aciduria (MMA) were studied in two cell lines from skin fibroblasts of patients with mitochondrial (GM00595) or cytosolic (GM10011) defects in the biosynthesis pathways of cobalamin coenzymes. The mtDNA level increased two-fold in GM00595 cells, which carry a mt defect in the adenosylcobalamin synthesis, whereas no appreciable change was found in GM10011 cells. The content of the two rRNAs 16S and 12S mtRNAs, normalized for the mtDNA copy number, decreased by 70% and 50% in GM00595 and GM10011, respectively. The normalized content of ND1, ND2 and CO I mRNAs decreased in GM00595, but was unchanged in GM10011. Respiratory chain complex activities measured in these two cell lines were not different from control activities. These data suggest that the maintenance of the mt function is due to doubling of mtDNA and that this compensatory response takes place only in those cells in which the greater reduction of the level of rRNA might have brought the content of these transcripts below the threshold value for optimal expression of the mt genome.
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Affiliation(s)
- P Cantatore
- Department of Biochemistry and Molecular Biology, University of Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, Italy
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20
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Roberti M, Musicco C, Polosa PL, Milella F, Gadaleta MN, Cantatore P. Multiple protein-binding sites in the TAS-region of human and rat mitochondrial DNA. Biochem Biophys Res Commun 1998; 243:36-40. [PMID: 9473475 DOI: 10.1006/bbrc.1997.8052] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To study the molecular mechanisms responsible for the regulation of mitochondrial DNA copy number, in vivo and in organello dimethyl sulfate footprinting experiments in human fibroblasts and rat liver mitochondria were carried out. By this approach we identified in both species two specific protein binding sites in the 3' region of the displacement loop of mitochondrial DNA. One site contains the TAS-D element of human and rat mitochondrial DNA; the other covers TAS-C and TAS-B in human, whereas in rat it comprises part of TAS-B. We suggest that the protected sequences might be the site of action of protein factors involved in the premature termination of mitochondrial DNA heavy-strand synthesis.
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Affiliation(s)
- M Roberti
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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21
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Lezza AM, Cormio A, Gerardi P, Silvestri G, Servidei S, Serlenga L, Cantatore P, Gadaleta MN. Mitochondrial DNA deletions in oculopharyngeal muscular dystrophy. FEBS Lett 1997; 418:167-70. [PMID: 9414119 DOI: 10.1016/s0014-5793(97)01374-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The deletions in the mitochondrial DNA from skeletal muscle samples of two oculopharyngeal muscular dystrophy cases were studied using polymerase chain reaction techniques. The 4977 bp 'common deletion' was present in both specimens, exceeding the corresponding values of similarly aged, healthy controls. In the two samples multiple different mitochondrial DNA deletions, some case-specific and present at quite high, although not pathogenetic levels, were observed. The results suggest that mitochondrial DNA deletions, and the 'common deletion' in particular, might be a sensitive and early marker of a generalized mitochondrial suffering, due to a variety of pathological and physiological causes.
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Affiliation(s)
- A M Lezza
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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22
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Roberti M, Musicco C, Loguercio Polosa P, Gadaleta MN, Quagliariello E, Cantatore P. Purification and characterization of a mitochondrial, single-stranded-DNA-binding protein from Paracentrotus lividus eggs. Eur J Biochem 1997; 247:52-8. [PMID: 9249008 DOI: 10.1111/j.1432-1033.1997.00052.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A binding protein for single-stranded DNA was purified from Paracentrotus lividus egg mitochondria to near homogeneity by chromatography on DEAE-Sephacel and single-stranded-DNA-cellulose. The protein consists of a single polypeptide of about 15 kDa. Glycerol gradient sedimentation analysis suggested that P. lividus mitochondrial single-stranded-DNA-binding protein exists as a homo-oligomer, possibly a tetramer, in solution. The protein shows a stronger preference for poly(dT) with respect to single-stranded M13, poly(dI) and poly(dC). Binding to poly(dA) takes place with much lower affinity. The binding-site size, determined by gel mobility-shift experiments with oligonucleotides of different length, is approximately 45 nucleotides. The binding to single-stranded DNA occurs with low or no cooperativity and is not influenced by ionic strength. The protein has a very high affinity for the DNA: its apparent macroscopic association constant is 2x10(9) M(-1), a value which is the highest among the mitochondrial single-stranded-DNA-binding proteins characterized to date. The lack of cooperativity and the high association constant represent distinctive features of this protein and might be related to the peculiar mechanism of sea urchin mitochondrial DNA replication.
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Affiliation(s)
- M Roberti
- Department of Biochemistry and Molecular Biology, University of Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, Italy
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23
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Abstract
As a step toward the characterization of the main components of mitochondrial DNA replication apparatus in sea urchin, we report the identification of a DNA-helicase activity in Paracentrotus lividus mitochondria. The activity was detected in a protein fraction obtained by fractionating on DEAE-Sephacel a lysate of gradient purified mitochondria from paracentrotus lividus eggs. The mitochondrial helicase unwound, in the presence of ATP and Mg++, a 39-base oligonucleotide annealed to single-stranded M13mp18 (+) DNA. Its direction of movement is 3' to 5' with respect to the single stranded portion of the partial duplex DNA substrate. This polarity is similar to that exhibited by the Escherichia coli rep helicase and by the helicase from bovine brain mitochondria. These features suggest that the sea urchin mitochondrial helicase could function in enabling the polymerization of the H-strand during mitochondrial DNA replication.
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Affiliation(s)
- M Roberti
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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24
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Cantatore P, Daddabbo L, Fracasso F, Gadaleta MN. Identification by in Organello footprinting of protein contact sites and of single-stranded DNA sequences in the regulatory region of rat mitochondrial DNA. Protein binding sites and single-stranded DNA regions in isolated rat liver mitochondria. J Biol Chem 1995; 270:25020-7. [PMID: 7559632 DOI: 10.1074/jbc.270.42.25020] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Footprinting studies with the purine-modifying reagent dimethyl sulfate and with the single-stranded DNA probing reagent potassium permanganate were carried out in isolated mitochondria from rat liver. Dimethyl sulfate footprinting allowed the detection of protein-DNA interactions within the rat analogues of the human binding sites for the transcription termination factor mTERF and for the transcription activating factor mt-TFA. Although mTERF contacts were localized only at the boundary between the 16S rRNA/tRNA(Leu)UUR genes, multiple mtTFA contacts were detected. Contact sites were located in the light and the heavy strand promoters and, in agreement with in vitro footprinting data on human mitochondria, between the conserved sequence blocks (CSB) 1 and 2 and inside CSB-1. Potassium permanganate footprinting allowed detection of a 25-base pair region entirely contained in CSB-1 in which both strands were permanganate-reactive. No permanganate reactivity was associated with the other regions of the D-loop, including CSB-2 and -3, and with the mTERF contact site. We hypothesize that the single-stranded DNA at CSB-1 may be due to a profound helix distortion induced by mtTFA binding or be associated with a RNA polymerase pause site. In any case the location in CSB-1 of the 3' end of the most abundant replication primer and of the 5' end of the prominent D-loop DNA suggests that protein-induced DNA conformational changes play an important role in directing the transition from transcription to replication in mammalian mitochondria.
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Affiliation(s)
- P Cantatore
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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25
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Paradies G, Ruggiero FM, Petrosillo G, Gadaleta MN, Quagliariello E. Carnitine-acylcarnitine translocase activity in cardiac mitochondria from aged rats: the effect of acetyl-L-carnitine. Mech Ageing Dev 1995; 84:103-12. [PMID: 8788238 DOI: 10.1016/0047-6374(95)01636-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Age-related changes in mitochondrial fatty acids metabolism may underlie the progressive decline in cardiac function. The effect of aging and acute treatment with acetyl-L-carnitine on fatty acids oxidation and on carnitine-acylcarnitine translocase activity in rat heart mitochondria was studied. Rates of palmitoylcarnitine supported respiration as well as carnitine-carnitine and carnitine-palmitoylcarnitine exchange reactions were all depressed (approx. 35%) in heart mitochondria from aged rats. These effects were almost completely reversed following treatment of aged rats with acetyl-L-carnitine. Heart mitochondrial cardiolipin content was significantly reduced (approx. 38%) in aged rats. Treatment of aged rats with acetyl-L-carnitine restored the level of cardiolipin to that of young rats. It is suggested that acetyl-L-carnitine is able to reverse age-related decrement in mitochondrial carnitine-acylcarnitine exchange activity by restoring the normal cardiolipin content.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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26
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Petruzzella V, Fracasso F, Gadaleta MN, Cantatore P. Decrease of D-loop frequency in heart and cerebral hemispheres mitochondrial DNA of aged rat. Mol Chem Neuropathol 1995; 24:193-202. [PMID: 7632322 DOI: 10.1007/bf02962143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A quantitative analysis of the frequency of the supercoiled mitochondrial DNA molecules containing the D-loop in rat heart and cerebral hemispheres, at different ages, is presented. Both tissues of aged animals exhibit a remarkable reduction in the content of super-coiled D-loop containing molecules compared to the adults. This alteration could be responsible for the age-dependent reduction of mitochondrial DNA transcription previously observed in rat brain and heart.
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Affiliation(s)
- V Petruzzella
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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27
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Cantatore P, Roberti M, Pesole G, Ludovico A, Milella F, Gadaleta MN, Saccone C. Evolutionary analysis of cytochrome b sequences in some Perciformes: evidence for a slower rate of evolution than in mammals. J Mol Evol 1994; 39:589-97. [PMID: 7807548 DOI: 10.1007/bf00160404] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To obtain information relative to the phylogenesis and microevolutionary rate of fish mitochondrial DNA, the nucleotide sequence of cytochrome b gene in seven fish species belonging to the order of Perciformes was determined. Sequence analysis showed that fish mitochondrial DNA has a nucleotide compositional bias similar to that of sharks but lower compared to mammals and birds. Quantitative evolutionary analysis, carried out by using a markovian stochastic model, clarifies some phylogenetic relationships within the Perciformes order, particularly in the Scombridae family, and between Perciformes, Gadiformes, Cypriniformes, and Acipenseriformes. The molecular clock of mitochondrial DNA was calibrated with the nucleotide substitution rate of cytochrome b gene in five shark species having divergence times inferred from paleontological estimates. The results of such analysis showed that Acipenseriformes diverged from Perciformes by about 200 MY, that the Perciformes common ancestor dates back to 150 MY, and that fish mitochondrial DNA has a nucleotide substitution rate three to five times lower than that of mammals.
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Affiliation(s)
- P Cantatore
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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28
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Lezza AM, Boffoli D, Scacco S, Cantatore P, Gadaleta MN. Correlation between mitochondrial DNA 4977-bp deletion and respiratory chain enzyme activities in aging human skeletal muscles. Biochem Biophys Res Commun 1994; 205:772-9. [PMID: 7999111 DOI: 10.1006/bbrc.1994.2732] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The content of the mitochondrial DNA 4977-bp deletion and the respiratory chain enzyme activities were determined in the same human skeletal muscle specimens. A direct correlation between damage to mtDNA and bioenergetic deficiency was observed. The time-course of the appearance of the mtDNA deletion was followed. The highest percentage of mtDNA-deleted molecules was 0.26% and it was found in the eighties which corresponds to the age of the major reduction in the respiratory chain enzyme activities. Two samples with very low mitochondrial respiratory enzyme activities exhibited much higher levels of deletion compared to the similar age counterparts. Given, however, the low absolute level of the deletion also in these samples, we suggest that damage to the respiratory chain complexes, especially complex IV, might be the cause more than the effect of the increased number of mtDNA molecules bearing deletions in aged human skeletal muscle.
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Affiliation(s)
- A M Lezza
- Department of Biochemistry and Molecular Biology, Univ. of Bari, Italy
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29
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Paradies G, Ruggiero FM, Petrosillo G, Gadaleta MN, Quagliariello E. Effect of aging and acetyl-L-carnitine on the activity of cytochrome oxidase and adenine nucleotide translocase in rat heart mitochondria. FEBS Lett 1994; 350:213-5. [PMID: 8070566 DOI: 10.1016/0014-5793(94)00763-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of aging and treatment with acetyl-L-carnitine on the activity of cytochrome oxidase and adenine nucleotide translocase in rat heart mitochondria was studied. It was found that the activity of both these mitochondrial protein systems was reduced (by around 30%) in aged animals. Treatment of aged rats with acetyl-L-carnitine almost completely reversed this effect. Changes in the mitochondrial cardiolipin content appear to be responsible for these effects of acetyl-L-carnitine.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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30
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Paradies G, Ruggiero FM, Petrosillo G, Gadaleta MN, Quagliariello E. The effect of aging and acetyl-L-carnitine on the function and on the lipid composition of rat heart mitochondria. Ann N Y Acad Sci 1994; 717:233-43. [PMID: 8030840 DOI: 10.1111/j.1749-6632.1994.tb12093.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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31
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Gadaleta MN, Petruzzella V, Daddabbo L, Olivieri C, Fracasso F, Loguercio Polosa P, Cantatore P. Mitochondrial DNA transcription and translation in aged rat. Effect of acetyl-L-carnitine. Ann N Y Acad Sci 1994; 717:150-60. [PMID: 7518198 DOI: 10.1111/j.1749-6632.1994.tb12082.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- M N Gadaleta
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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32
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Polosa PL, Roberti M, Mustich A, Gadaleta MN, Cantatore P. Purification and characterization of a mitochondrial DNA-binding protein that binds to double-stranded and single-stranded sequences of Paracentrotus lividus mitochondrial DNA. Curr Genet 1994; 25:350-6. [PMID: 8082178 DOI: 10.1007/bf00351489] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A mitochondrial protein, able to specifically bind two double-stranded homologous sequences of sea-urchin mitochondrial DNA, has been partially purified from Paracentrotus lividus eggs. This protein, present at a low concentration, is a polypeptide of 40 kDa. One of the binding sequences, located in the main non-coding region, contains the replication origin of the mitochondrial DNA H-strand. By a combination of band-shift, DNase footprinting, and modification interference analyses with homologous and heterologous probes we identified YCYYATCAN(A/T)RC as the minimum sequence required for the binding. The protein also shows a single-stranded DNA-binding activity, as it is able to specifically interact with one of the strands of the binding sites. These features are consistent with a function of the protein in the modulation of sea-urchin mitochondrial DNA replication during the development stages.
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Affiliation(s)
- P L Polosa
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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33
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Affiliation(s)
- V Petruzzella
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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34
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Gadaleta MN, Rainaldi G, Lezza AM, Milella F, Fracasso F, Cantatore P. Mitochondrial DNA copy number and mitochondrial DNA deletion in adult and senescent rats. Mutat Res 1992; 275:181-93. [PMID: 1383760 DOI: 10.1016/0921-8734(92)90022-h] [Citation(s) in RCA: 170] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to understand the cause of the reduced mitochondrial DNA transcription in heart and brain of senescent rat previously reported, we focused our attention on the content and structure of rat mitochondrial DNA in adult and senescent rats. The estimate of the mtDNA copy number in liver, heart and brain of adult and senescent rats showed that in all organs examined the senescent individuals have a mtDNA content higher than the adult counterparts. The analysis of mtDNA structural changes involved the search for point mutations and large deletions. As for the first case, the determination of the nucleotide sequence of many independent clones containing two mtDNA restriction fragments isolated from rat cerebral hemispheres did not show any sequence difference between adult and senescent individuals. However, analysis of mtDNA deletions by the polymerase chain reaction in liver and brain of adult and senescent rats identified a small population of mtDNA molecules harboring a deletion of 4834 bp. The estimate of the proportion of deleted molecules in the liver showed that they represent 0.02% and 0.0005% of total mtDNA in senescent and adult rat liver respectively. Therefore, a mtDNA deletion also accumulates in the rat during aging. This result supports the hypothesis of the accumulation of deleted mtDNA molecules in aging. However, the low percentage of deleted mtDNA molecules already found and the reversibility of the reduced mitochondrial DNA transcription in senescent rat raise doubts on the primary role of the irreversibly damaged mtDNA molecules in aging. Deleted mtDNA molecules along with changes caused by lipid peroxidation of mitochondrial membranes might contribute to the overall decline of mitochondrial function.
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Affiliation(s)
- M N Gadaleta
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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35
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Ruggiero FM, Cafagna F, Petruzzella V, Gadaleta MN, Quagliariello E. Lipid composition in synaptic and nonsynaptic mitochondria from rat brains and effect of aging. J Neurochem 1992; 59:487-91. [PMID: 1629722 DOI: 10.1111/j.1471-4159.1992.tb09396.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The cholesterol, phospholipid, and fatty acid compositions in synaptic and nonsynaptic mitochondria from rat brains and the effect of aging were studied. Both cholesterol and phospholipid contents were found to be significantly different in synaptic compared to nonsynaptic mitochondria. In both types of brain mitochondria, aging decreases the cholesterol content by 27% and the phospholipid content by approximately 12%. The difference between these decreases observed in the organelles causes decreases in the cholesterol/phospholipid molar ratios for synaptic and nonsynaptic mitochondria of 17 and 19%, respectively. Also, the phospholipid composition is significantly different in synaptic compared to nonsynaptic mitochondria. Among phospholipids, only the cardiolipin fraction showed a significant decrease (26%) in nonsynaptic mitochondria from the brains of aged rats. Instead, the fatty acid composition was not significantly different in synaptic compared to nonsynaptic mitochondria. The 21% aging decrease in linoleic acid (18:2), observed only in nonsynaptic mitochondria, may be related to a decrease in cardiolipin, which contains a large amount of this fatty acid.
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Affiliation(s)
- F M Ruggiero
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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36
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Paradies G, Ruggiero FM, Gadaleta MN, Quagliariello E. The effect of aging and acetyl-L-carnitine on the activity of the phosphate carrier and on the phospholipid composition in rat heart mitochondria. Biochim Biophys Acta 1992; 1103:324-6. [PMID: 1543717 DOI: 10.1016/0005-2736(92)90103-s] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of aging and treatment with acetyl-L-carnitine on the activity of the phosphate carrier and on the phospholipid composition in rat heart mitochondria was studied. It was found that the activity of the phosphate carrier was reduced by aging. Treatment of aged rats with acetyl-L-carnitine reversed this effect. The mitochondrial level of cardiolipin was decreased with aging. Treatment of aged rats with acetyl-L-carnitine restored the level of cardiolipin to that of young rats. It is proposed that acetyl-L-carnitine may restore the correct phospholipid composition (cardiolipin level) of the mitochondrial membrane, altered by aging, thereby restoring the activity of the phosphate carrier.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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37
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Roberti M, Mustich A, Gadaleta MN, Cantatore P. Identification of two homologous mitochondrial DNA sequences, which bind strongly and specifically to a mitochondrial protein of Paracentrotus lividus. Nucleic Acids Res 1991; 19:6249-54. [PMID: 1956785 PMCID: PMC329135 DOI: 10.1093/nar/19.22.6249] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Using a combination of band shift and DNasel protection experiments, two Paracentrotus lividus mitochondrial sequences, able to bind tightly and selectively to a mitochondrial protein from sea urchin embryos, have been found. The two sequences, which compete with each other for binding to the protein, are located in two genome regions which are thought to contain regulatory signals for mitochondrial replication and transcription. A computer analysis suggests that the sequence TTTTRTANNTCYYATCAYA, common to the two binding regions, is the minimal recognition signal for the binding to the protein. We discuss the hypothesis that the protein binding capacity of these two sequences is involved in the control of sea urchin mtDNA replication during developmental stages.
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Affiliation(s)
- M Roberti
- Dipartimento di Biochimica e Biologia Molecolare, Universita' di Bari, Italy
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38
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Fernandez-Silva P, Petruzzella V, Fracasso F, Gadaleta MN, Cantatore P. Reduced synthesis of mtRNA in isolated mitochondria of senescent rat brain. Biochem Biophys Res Commun 1991; 176:645-53. [PMID: 1709016 DOI: 10.1016/s0006-291x(05)80233-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A system for studying RNA synthesis in isolated mitochondria from rat brain was set up to investigate the mechanisms responsible for the age-dependent reduction of mtRNA content. In the presence of an appropriate incubation buffer both synaptic and non-synaptic mitochondria from cerebral hemispheres were able to synthesize and process mtRNA in a way quantitatively and qualitatively similar to the in vivo transcription. The comparison of the electrophoretic pattern of mtRNAs synthesized by adult and senescent rat showed, in the senescent rat, a 50% reduction in the mtRNA synthesis rate relative to the adult value. This indicates that the age-dependent decrease of the mtRNA content is linked to a lower efficiency of the mt transcription.
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Affiliation(s)
- P Fernandez-Silva
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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39
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Gadaleta MN, Petruzzella V, Fracasso F, Fernandez-Silva P, Cantatore P. Acetyl-L-carnitine increases cytochrome oxidase subunit I mRNA content in hypothyroid rat liver. FEBS Lett 1990; 277:191-3. [PMID: 2176613 DOI: 10.1016/0014-5793(90)80841-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of acetyl-L-carnitine on the quantity of the messenger RNA for the subunit I of cytochrome oxidase in the liver mitochondria of hypothyroid rat was measured by Northern blot and solution hybridization. Three hours after pre-treatment of hypothyroid rat with acetyl-L-carnitine, the level of the transcript increased strongly. This effect was also obtained when acetyl-L-carnitine was administered to T3 pre-treated hypothyroid rats. These results add further evidence to the suggestion that acetyl-L-carnitine is able to stimulate mitochondrial transcription under altered metabolic conditions.
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Affiliation(s)
- M N Gadaleta
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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Ruggiero FM, Cafagna F, Gadaleta MN, Quagliariello E. Effect of aging and acetyl-L-carnitine on the lipid composition of rat plasma and erythrocytes. Biochem Biophys Res Commun 1990; 170:621-6. [PMID: 2383260 DOI: 10.1016/0006-291x(90)92137-o] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The effect of aging and treatment with acetyl-L-carnitine on the lipid composition of rat plasma and erythrocytes was studied. It was found that aging increases the levels of free and esterified cholesterol. Fatty acid patterns in the plasma of aged rats show remarkable alterations when compared with control rats. These changes reverted to normal after three hours of acetyl-L-carnitine treatment. No significant differences in the erythrocyte lipid pattern of young and aged rats were observed. This study provides the first proof that acetyl-L-carnitine probably acts by lowering free and esterified cholesterol and arachidonic acid (20:4) levels in the plasma.
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Affiliation(s)
- F M Ruggiero
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Cantatore P, Roberti M, Loguercio Polosa P, Mustich A, Gadaleta MN. Mapping and characterization of Paracentrotus lividus mitochondrial transcripts: multiple and overlapping transcription units. Curr Genet 1990; 17:235-45. [PMID: 1692770 DOI: 10.1007/bf00312615] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This paper reports the mapping of both mature and precursor Paracentrotus lividus mitochondrial transcripts. Several mtRNAs were found to have 5' and 3' termini which differ from those inferred through DNA sequencing (Cantatore et al. 1989). The 3' ends of the two rRNAs (12S and 16S) overlap with the downstream transcripts (tRNAGlu and CoI mRNA) by 5 and 10 nt respectively. The 132 nt non-coding region is extensively transcribed: in particular it contains a 124 nt RNA and the 5' end of a possible precursor of 13 clustered tRNAs. This latter overlaps by 7 nt with the 3' end of the 124 nt RNA. In addition to the mature RNAs, 32 high molecular weight RNAs, which are probably the precursors of the smaller more abundant mature species, were detected by Northern blotting. The mapping of these transcripts indicates that they are processed at the level of tRNA or tRNA-like sequences and suggests the existence of two transcription initiation sites upstream of the ND1 and the cytochrome b genes respectively. In the light of these results it appears that P. lividus mitochondrial DNA transcription takes place via multiple and probably overlapping transcription units. Moreover, the wide variation in the steady-state levels of the mature mRNAs indicates that sea urchin mitochondrial DNA expression is also regulated at the level of RNA decay.
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Affiliation(s)
- P Cantatore
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Gadaleta MN, Petruzzella V, Renis M, Fracasso F, Cantatore P. Reduced transcription of mitochondrial DNA in the senescent rat. Tissue dependence and effect of L-carnitine. Eur J Biochem 1990; 187:501-6. [PMID: 2154375 DOI: 10.1111/j.1432-1033.1990.tb15331.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A quantitative study on the effect of senescence on mitochondrial DNA expression has been carried out by measuring the levels of the 12S rRNA and of the mRNA for the subunit I of cytochrome oxidase in several tissues of adult and senescent rats. The concentration of both RNA species/mitochondrial DNA molecule is significantly reduced in senescent brain and heart, as opposed to the respective adult tissues. No appreciable variation occurs in the liver. A 1-h pretreatment with acetyl-L-carnitine brings back the level of senescent brain and heart transcripts to that of adult tissues. The same treatment of adult rats does not cause significant changes in mitochondrial RNA content. These results suggest that the age-dependent impairment of both heavy-strand mitochondrial DNA transcription units is related to altered environmental conditions which acetyl-L-carnitine, a substance which acts by stimulating, directly or indirectly, the energy metabolism, is able to remove.
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MESH Headings
- Acetylcarnitine/pharmacology
- Aging/genetics
- Aging/metabolism
- Animals
- Blotting, Northern
- Brain/drug effects
- Carnitine/analogs & derivatives
- DNA/genetics
- DNA/isolation & purification
- Electron Transport Complex IV/genetics
- Mitochondria/drug effects
- Mitochondria/enzymology
- Mitochondria/metabolism
- Mitochondria, Heart/drug effects
- Mitochondria, Liver/drug effects
- Nucleic Acid Hybridization
- Plasmids
- RNA, Messenger/genetics
- RNA, Messenger/isolation & purification
- RNA, Ribosomal/genetics
- RNA, Ribosomal/isolation & purification
- RNA, Transfer/genetics
- RNA, Transfer/isolation & purification
- Rats
- Rats, Inbred F344
- Transcription, Genetic/drug effects
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Affiliation(s)
- M N Gadaleta
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari e Centro Studi sui Mitocondri e Metabolismo Energetico, Bari, Italy
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Cantatore P, Roberti M, Rainaldi G, Gadaleta MN, Saccone C. The complete nucleotide sequence, gene organization, and genetic code of the mitochondrial genome of Paracentrotus lividus. J Biol Chem 1989; 264:10965-75. [PMID: 2544576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The 15,697-nucleotide sequence of Paracentrotus lividus mitochondrial DNA is reported. This genome codes for 2 rRNAs, 22 tRNAs, and 12 mRNAs which specify 13 subunits of the mitochondrial inner membrane respiratory complexes. The gene arrangement differs from that of other animal species. The two ribosomal genes 16 S and 12 S are separated by a stretch of about 3.3 kilobase pairs which contains the ND1 and ND2 genes and a cluster of 15 tRNA genes. The ND4L coding sequence is not contained in the ND4 mRNA but has its own mRNA which maps between the tRNA(Arg) and the Co II genes. The main noncoding region, located in the tRNA gene cluster, is only 132 nucleotides long, but contains sequences homologous to the mammalian displacement loop. Other short noncoding sequences are interspersed in the genome: they contain a conserved AT consensus which probably has a role in transcription or RNA processing. As regards the mitochondrial genetic code, the codons AGA and AGG specify serine and are recognized by a tRNA with a GCU anticodon, whereas AUA and AAA code for isoleucine and asparagine rather than for methionine and lysine. Except for ND4L which starts with AUC and ATPase 8 which starts with GUG, AUG is used as the initiation codon. In 11 out of 13 cases the genes terminate with the canonical stop codons UAA or UAG. These observations suggest that during invertebrate evolution each lineage developed its own mechanism of mitochondrial DNA replication and transcription and of RNA processing and translation.
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Affiliation(s)
- P Cantatore
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Renis M, Cantatore P, Loguercio Polosa P, Fracasso F, Gadaleta MN. Content of mitochondrial DNA and of three mitochondrial RNAs in developing and adult rat cerebellum. J Neurochem 1989; 52:750-4. [PMID: 2465379 DOI: 10.1111/j.1471-4159.1989.tb02518.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The content of DNA and of 16S rRNA and of two mRNAs, i.e., the mRNA for the cytochrome c oxidase subunit I and the mRNA for one subunit of the NADH dehydrogenase (ND4), in free (nonsynaptic) mitochondria of developing and adult rat cerebellum has been determined. During postnatal development, DNA content of free (nonsynaptic) mitochondria increases 10 times from 1 to 30 days of age whereas, in adult rats, it is about 60% compared to that found in 30-day-old rats. The total content of each RNA species studied also increases during development. However, when the content of each RNA is expressed per mtDNA molecule, rRNAs and mRNAs behave differently: 16S rRNA level does not change during development and it is not significantly different from that of the adult rat, whereas the level of mRNAs is higher during development than in the adult rat and changes with age. These results are discussed in light of mitochondrial biogenesis in rat cerebellum during development and of the regulation of the mitochondrial DNA transcription process.
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Affiliation(s)
- M Renis
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Cantatore P, Loguercio Polosa P, Mustich A, Petruzzella V, Gadaleta MN. Faithful and highly efficient RNA synthesis in isolated mitochondria from rat liver. Curr Genet 1988; 14:477-82. [PMID: 2852068 DOI: 10.1007/bf00521272] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Isolated rat liver mitochondria in the presence of an appropriate incubation buffer are able to support DNA transcription and RNA processing in a way qualitatively and quantitatively similar to that used by intact cells. This system is also able to synthesize an RNA species of 155-175 nucleotides which probably corresponds to the 7S RNA, a type of RNA found so far only in growing cells. The role of this RNA in the mitochondrial replication and transcription processes, in relation to the cell metabolism, is discussed.
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Affiliation(s)
- P Cantatore
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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Abstract
We have determined the base sequence of the restriction fragment Bam1-2 (3,593) of Paracentrotus lividus (sea urchin) mtDNA. This fragment contains, in addition to genes previously identified (part of the 12S rRNA, ND1 and part of the ND2 mRNA), a cluster of 15 tRNA genes located between the 12S and ND1 genes. Also to be found in the tRNA gene cluster, between the tRNA(Thr) and tRNA(Pro) genes, is a sequence of 134 bp which constitutes the only non-coding region of this DNA so far identified. The distinctive organization of the tRNA genes and the extreme size reduction of the non-coding region suggest the existence of unique mechanisms for the regulation of gene expression in this organism.
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Affiliation(s)
- P Cantatore
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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Cantatore P, Gadaleta MN, Roberti M, Saccone C, Wilson AC. Duplication and remoulding of tRNA genes during the evolutionary rearrangement of mitochondrial genomes. Nature 1987; 329:853-5. [PMID: 3670390 DOI: 10.1038/329853a0] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
During the evolution of sea urchins, a transfer RNA gene lost its tRNA function and became part of a protein-coding gene. This functional loss of a tRNA with specificity for one group of leucine codons (CUN, where N is any base) was accompanied by the gain of a new tRNA with that specificity. The new tRNA gene for CUN codons appears to have evolved by duplication and divergence from a tRNA gene specific for another group of leucine codons (UUR, where R is a purine). These proposals account for (1) the strong sequence resemblance between the modern tRNA genes for CUN and UUR codons in Paracentrotus, (2) the altered location of the CUN gene in mitochondrial DNA of this urchin, and (3) the persistence of a 72-base pair sequence containing a trace of the old CUN gene at its original location. The old CUN gene now codes for an extra 24 amino acids at the amino end of subunit 5 in NADH dehydrogenase. Besides giving clues about the mechanisms by which tRNA genes move during mitochondrial DNA evolution, this finding leads us to propose a pathway relating the arrangements of other genes in mitochondrial DNAs from four animal phyla.
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Affiliation(s)
- P Cantatore
- CSMME del CNR e Dipartimento di Biochimica e Biologia Molecolare, Universita di Bari
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Cantatore P, Flagella Z, Fracasso F, Lezza AM, Gadaleta MN, de Montalvo A. Synthesis and turnover rates of four rat liver mitochondrial RNA species. FEBS Lett 1987; 213:144-8. [PMID: 2435574 DOI: 10.1016/0014-5793(87)81480-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The synthesis and turnover rates of the two 12 S and 16 S mt rRNAs and of the mt mRNAs for subunits I and III of cytochrome oxidase have been determined by measuring the kinetics of incorporation of [3H]uridine in the mtRNA of rat hepatocytes. All the RNA species examined have approximately the same turnover (t1/2 approximately 100 min) and therefore the rate of synthesis, which is about 10-times higher for the rRNAs, seems to be the factor responsible for the different mt rRNA and mRNA steady-state levels.
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Abstract
The mitochondrial DNA (mtDNA) from Paracentrotus lividus (sea urchin) eggs, a circular molecule of about 15,500 bp, has been cloned in plasmid vectors after cleavage with various restriction enzymes. By a combination of Northern blot hybridization and nucleotide sequence analysis we have characterized most of the P. lividus mitochondrial transcripts and determined the basic gene organization of the mtDNA. The nucleotide sequence of a gene for one NADH dehydrogenase (ND) subunit, ND4L, has also been determined. Our results show the existence of a novel gene order. The 12S and 16S rRNA genes are not contiguous but are separated from each other by ND1 and ND2 genes. The ND4L gene is not adjacent to ND4 but is located between the tRNAArg gene and the gene for subunit II of cytochrome oxidase (CoII). The tRNA genes are reshuffled and contrary to all vertebrate mitochondrial genomes studied so far, there are no intergenic regions between the tRNAPhe and the cytochrome b genes. These characteristics suggest a peculiar mechanism for the regulation of gene expression in this organism and provide information on the evolution of the mitochondrial genetic system in animal cells.
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Cantatore P, Polosa PL, Fracasso F, Flagella Z, Gadaleta MN. Quantitation of mitochondrial RNA species during rat liver development: the concentration of cytochrome oxidase subunit I (CoI) mRNA increases at birth. Cell Differ 1986; 19:125-32. [PMID: 2428507 DOI: 10.1016/0045-6039(86)90069-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A quantitative study on the concentration of mitochondrial DNA and two species of mtRNA, the ribosomal (16S rRNA) and messenger (CoI mRNA) has been carried out in rat liver between -3 and 14 days of age. The cellular content of mitochondrial DNA begins to increase at one day of life and goes up linearly until 14 days of age. The cellular level of 16S rRNA and CoI mRNA changes during development: the 16S rRNA increases linearly after birth, whereas CoI mRNA shows a peak at birth and thereafter remains more or less constant. The concentration of 16S rRNA per mitochondrial DNA molecule remains substantially unchanged during development, whereas that of CoI mRNA increases before birth and, at birth, reaches values higher than in adults. These results support an independent regulation of mitochondrial rRNA and mRNA level in rat liver mitochondria during development.
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